New Study Finds Popular Heartburn Drugs Lower Magnesium Levels

A new study is confirming a link between popular heartburn drugs called proton pump inhibitors – Nexium, Dexilant, Prilosec, Zegerid, Prevacid, Protonix, AcipHex etc. – and a condition called hypomagnesemia. The study, which was reported at the annual Digestive Disease Week conference in May, follows a health alert issued by the U.S. Food & Drug Administration (FDA) earlier this year regarding hypomagnesaemia and proton pump inhibitors.

Hypomagnesemia – low serum magnesium levels – can result in serious health problems including muscle spasm, irregular heartbeat and convulsions. This new study, presented by Dr. Jen-Tzer Gau, chair of geriatric medicine/gerontology at Ohio University College of Osteopathic Medicine, involved 1,317 patients at a rural community hospital in southeast Ohio. Of those, 464 used proton pump inhibitors, while 853 did not. Upon admission, the mean magnesium level 1.91 mg/dL among proton pump inhibitor users, compared with 2.00 mg/dL among nonusers. Following their analysis, the researchers determined that proton pump inhibitor therapy was associated with an increased risk of hypomagnesemia occurrence (crude odds ratio 2.41), and the association remained significant after adjustment for all confounders.

The odds ratio was 2.29 after adjustment for age, sex, and serum albumin levels and was 2.21 after researchers also adjusted for serum levels of potassium, calcium, and creatinine; supplementation with potassium and magnesium; history of diabetes and chronic obstructive pulmonary disease; and diuretic use, Dr. Gau said. In addition to those factors, the fully adjusted model also accounted for other variables, including history of heart failure and coronary artery disease, a diagnosis of acute gastrointestinal illness, and use of iron supplements, antipsychotics, antihistamines, narcotics, NSAIDs, antidepressants, beta2-agonist bronchodilators, inhaled corticosteroids, and oral laxatives.

Limitations of the study include the fact that most of the patients were white, the lack of data on duration of proton pump inhibitor use, the Dr. Gau said.

The study confirms the information contained in an FDA alert regarding hypomagnesemia and proton pump inhibitors that was issued in March. At the time, the agency said its review had uncovered 38 cases of hypomagnesemia among proton pump inhibitors in the Adverse Event Reporting System, and 23 other cases in the literature. Some cases were reported in adult patients taking proton pump inhibitors for at least three months, but most cases occurred after a year of treatment. Approximately one-quarter of these cases required discontinuation of proton pump inhibitor treatment in addition to magnesium supplementation.

As we reported at the time, the FDA recommended that healthcare providers consider obtaining serum magnesium levels before their patients begin treatment with prescription proto pump inhibitors. The agency said they should also consider periodic testing if patients are also being treated with medications such as digoxin, diuretics or drugs that may cause hypomagnesemia. In digoxin patients especially, low magnesium can increase the likelihood of serious side effects.